The diversions go via Wakefield Kirkgate. The Huddersfield to Sheffield time is amazing (I think 40 mins). Could be faster if they replaced the curve at Horbury. Which I think will give about a 1 hour 10 minute Sheffield to Manchester time. Not shabby at all.
(I can’t find a timetable example right now)
If they went via Penistone would need a reversal at Huddersfield.
Penistone is a non-starter over the single track sections. Diversion of the fast TPE services via Wakefield is relatively routine but adds almost half an hour to the normal TPE journey between Sheffield and Manchester, as it will on the next two Sundays.
EMR usually bus from Chesterfield and Sheffield to Stockport.
Northern may bus between New Mills Central and Sheffield - which takes for ever (1 hour 50 just for that section then change to train taking another 30 minutes plus connection time) and most who know will avoid.
A protracted blockade would decimate commuter traffic between the the two cities, add a further nail in the rail option from the east to Manchester Airport and severely damage the growing leisure market for the Hope Valley.
But don't be over concerned about passengers. How is limestone and cement traffic to be diverted?
My guess is that some bi-mode option is most likely. Electrify up to the Chinley end of Cowburn Tunnel and the Totley end of Totley Tunnel. Possibly electrify from Edale to Grindleford. The section from Sheffield through Dore would be a natural follow on from the MML scheme, as overrun probably part of it.
Last might the final two segments of the lift shaft towers at Dore were put in place and preparations are in hand to add the steps and walkway during the next few weeks, particularly the next two Sundays.